本論文目的為設計應用於全球數位電視廣播接收(470 MHz~862 MHz)之微型化天線。 本天線是利用50 Ω微帶線饋入,在微帶線接的地面開槽使微帶線的返回電流路徑延長,達到輻射的效果。在接地面設計七個共振路徑,激發多個諧振頻率達到寬頻的效果。利用開路的微帶線來激發天線模態,且開路微帶線與接地面之間互面耦合引近電容效應達到縮小的目的。另外在開路微帶線上加入矩形金屬片來達到阻抗配匹的效果。本天線的輻射場型具有全方性的特性,能達到全向性接收的優點。本天線經實際製作量測後其實驗結果與量測結果一致。 為了加強接收效能故本天線結合了低雜訊放大器,利用低雜訊放大器將天線接收的訊號功率強度提升,增加使用者收訊的品質。最後,實際製作將電路部分整合於天線的接地面上,驗證接收信號強度提升的效果。本天線的體積僅為20 × 20 × 0.8 mm3,結合低雜訊放大器後20 × 30 × 0.8 mm3。
A novel broadband antenna miniaturization is presented in this thesis. The antenna is proposed for operating at whole world DTV reception band (470 MHz ~ 860 MHz). This antenna used the 50 Ω microstip line to feed, In microstip line’s ground plane slotting let microstip line return current path increase to radiation effect. To achieve broadband structure, the proposed antenna is composed of seven resonances path in the ground plane. To achieve compact structure, the proposed antenna is use signal line and ground plane coupling induce the capacitance effect. The impedance matching and bandwidth for the presented antenna are mainly affected by sheet metal on signal line. The antenna can get omnidirectional radiation pattern in the whole frequency band. The measurement result is agree with simulation. In order to enhance receiver receiving performance for this antenna in DTV signal receptions, the LNA is used to increase the receiving signal power intensity. Finally, the LNA be fabricated and integrated in the ground plane to prove the receiver signal power intensity by practical measurement. The designed antenna with overall size of only 20 × 20 × 0.8 mm3, and combined the LNA overall size of only 20 × 30 × 0.8 mm3.